I could be wrong, but it seems that most themes for coasters(and areas) are one of three things:
1.Fictional(Big Bad Wolf, Kraken, Batman)
2.Exclusively non-negative (Rock'n'Rollercoaster, general time periods)
3.Far removed from modern culture.
In other words, parks seek to theme rides to something that has the least possible chance of being negatively perceived. WWII is closely tied with things such as the holocaust and the very high death counts on the eastern front. Add to that the fact that there are still people alive who are closely connected with the conflict and I really don't think that there is much of a chance of a park theming things to that event. The only thing that I can even think of related to WWI is the little plane kiddie rides.
I could be over thinking this, but on the other hand, it is a very well known part of our culture that isn't represented in a theme park at all. One way that I could see something like this happening is if Disney were to make a Captain America themed area. That makes it just fictional enough to work I'd say. Chances of that though are very low, esp. given the complicated marvel licensing in which Universal owns most of the Avengers rights in theme parks.
The other thing I was thinking of is that while I was working in public affairs, I became very aware of how other nations view the war. Most are absolutely fine with hearing about it. There is one notable exception: Japan. While there is a range of ways that they react to mention of WWII, a good number of them prefer not to see or hear anything about it, especially the older folks. While KD is not a very "international" park, it isn't infeasible that such a thing would be considered.
As such, I don't see a WWII theme being carried out. It could be very cool, but overall, it doesn't seem very theme-park like.
